Magnetic resonance imaging (MRI) is experiencing rapid growth as a clinical diagnostic tool. This development has resulted in the exposure of an increasing patient and health care population to a wide variety of static and time-varying electromagnetic fields. In addition, technical developments such as high field imaging systems, fast cardiac imaging, and localized magnetic resonance spectroscopy (MRS) often establish concentrated electric and magnetic fields in local issue regions. While the present generation (0.06 to 1.95 T) of MR imaging systems has an excellent safety record, the scientific understanding of the interaction of radiofrequency and magnetic fields with biological systems is incomplete. The purpose of the proposed scientific meeting is to examine carefully the potential health hazards and safety aspects of the static and dynamic fields generated by MR imaging and spectroscopy systems. In particular, emphasis will be on new and emerging techniques which employ fields that exceed those in existing imaging systems. These conditions include intense static magnetic fields (4T), larger magnetic fields gradients (1OOmT/m), and higher RF frequencies (200 MHz). of particular concern are the rapidly switched magnetic fields (10 T/s) that occur during fast imaging sequences and the higher absorption of radiofrequency power (5 Watts/kg) which occurs which decoupling pulses and surface coils are used in spectroscopy. These fields conditions may produce biological responses not present in the current generation of imaging systems. An important goal of the proposed meeting is to examine the potential hazards to patients and staff associated with such biological effects.